Tag Archives: Mac OS

Review ~ Disk Drill 3


File purgatory — Disk Drill 3 is the kind of software that can almost literally save your life if you have deleted files, or something went wrong with computer and files have disappeared. Macs typically don’t actually delete the file itself. The usual process is that when you Empty Trash, the links to the files are obliterated, but the files themselves are there, hidden. The space they occupy then becomes listed as free space and if you need to save a new file, or install a, large app, import a movie etc and it needs that space, the file will ‘overwrite’ that space, making whatever file existed there before irretrievable.
For this reason, various software (or the ‘Secure Empty Trash option on Mac that still have non SD hard drives) will write zeroes over where files were to make them irretrievable.
You can do this in Disk Utility, for example, the Apple ute that sits in the Utilities folder in Applications. In this case, depending on what kind of hard drive your Mac has as its main drive and what software integration you are on, you can either choose Erase and then click Security Options to write the zeroes, and older versions of the utility let you write zeroes over empty space without erasing the entire HD, although my version no longer allows this.
You should always do this before you pass your Mac on to someone else or sell it, for example, so they can’t reconstruct all those spreadsheets showing there you have spirited away those millions … Erase the Hard Drive with Security options, reinstall the OS from scratch and then sell it or otherwise pass it on.

Anyway, software like Disk Drill can rebuild links to files that have not yet been overwritten. It’s a free download from Clever Files and this is clever indeed – with the free version, initiate a scan to see if those files you lost are retrievable. Once upon a time, you then had to upgrade to Pro (for US$89) to actually retrieve them, which is better than buying the software to then discover the files aren’t retrievable. But boy, does Clever Files have a deal for you … because this free version does recovery as well.

Disk Drill 3 for Mac (I reviewed the previous version in November 2015) can recover not just from your internal hard drive but from almost anything that plugs into your Mac: backup drives, other storage external drives, USB ‘thumb drives’, many camera cards and even, with this latest version, from iOS devices. This will get back photos, videos, texts, contacts and messages. It can even scan and recover from Kindle and Android devices you plug into your Mac.

Additionally, there are various disk management abilities that come with it, which let you find duplicates, monitor the health of all those drives and to instil some level of protection. These tools, all free as well, include Disk Health, Mac Cleanup, Duplicate Finder, Recovery Drive, Data Protection and Data Backup. It would be worth the price of Disk Drill 3 for these anyway … oh yeah, but it’s free. So that’s a no-brainer.

In operation, install Disk Drill 3, select the drive to recover from, click Recover next to it, wait for the scan to conclude (this can take a long time depending on how big, full or fast that media is) and then tick the files you wish to retrieve from purgatory, and click Recover again. A cogwheel icon next to Recover lets you further configure how deep you wan this operation to go (main picture, above).
Last time I reviewed it, I said it looked like a port from a PC app – in other words, it looked (and felt a little like) it had been developed for PC and then ported over and modified into a Mac app. This version is better: it feels faster, looks slicker and its features are easier to find and use. It can recover files from different types of media too – formatted for Apple’s Mac OS Extended, the default, of course, but also HFS+, NTFS, FAT (Windows’s usual format) and more, and if you scroll downwards at this link, there are several sorts of recovery methods covered for you.

The Pro version — As I said, this is one hell of a deal considering it does so much, well, and with an improved more Apple-like interface. But you can further should you wish, but paying for the Pro version. That’s US$89 for a single user or US$399 for Enterprise with full support for everyone in your company. This version offers free lifetime upgrades (you can pay another US$29 as an add-on to get that with the Pro version). Both have two levels of scanning (normal plus Deep, for a greater level or recovery) and they can rebuild a lost HFS+ catalogue, search deleted partitions and handle even more media types with more configurable searches. Upgrades from previous pro versions are $50 off, and there’s even a competitive upgrade (from another company’s product) for US$50 off (Education, Non Profit and Government copies have a $20 discount).

Conclusion — This is a fantastic new version that will make you feel more secure in almost every way about your precious hard drives and other media.

What’s great — The free version does almost everything now, and has additional tools to scan and recovery, including disk protection and duplicate finding, plus cleaning of all those annoying sludge files that gum up your system (and other) drives. And it’s better looking and easier to use. For documents and photos, this is very effective.

What’s not — Not as good at recovering video and music files.

Needs — Anyone who likes free software that’s really well written and effective.

Disk Drill 3 — The standard Free already does a lot and includes scan and recovery plus handy disk management utilities; US$89 for Pro adds features and US$399 gets you the Enterprise version for a whole company’s Macs with lifetime free upgrades.

System — Requires Mac OS X 10.8.5+. (Other versions are still available for older Macs.)

Further information — Clever Files site.

Five Tip Friday ~ Images, instant video, locked images in the trash, on SD cards


1/ How to create an iCloud Shared Album — iCloud Photo Library stores every photo and video you make, then keeps them up to date on all your OS X and iOS devices. Any edits you make are automatically updated everywhere. And iCloud Photo Sharing makes it easy to share those photos and videos with others – you know, you have a batch of photos, you want Aunt Mary to see them, but she lives in Glasgow and you line in Porirua ….
— Open the Photos app on your Mac, iPhone, or iPad and select one or more photos.
— Click on the Share Icon, then choose iCloud Photo Sharing.
A new window will pop up. You can add a caption or comment to the photos.
— Click New Shared Album. (If you’re setting up your Shared Album in iOS, you’ll tap Shared Album first, and then New Shared Album.)
— Name your iCloud Shared Album.
Now you can invite the folks you wish to share it with by using the box in the middle. You can invite people via their email address or iMessages number, or select names from your Contacts list.
When the info is all filled out, click Create, and you’re good to go. You can continue to add photos to your Shared Album, and they’ll beavailable to those you invited when you created the album (from Apple World Today).

2/ Use a keyboard shortcut for Display Mirroring — There’s a keyboard shortcut you should learn—Command-F1. This combo turns display mirroring off and on, so if you need to temporarily see your Dock or your open windows on both displays, it’ll let you do that. This is just a quick way to, well, mirror the functionality of System Preferences>Displays>Arrangement>Mirror Displays.
To put things back the way you had them, press Command-F1 again.
(f this doesn’t seem to be working for you, check out your options at System Preferences>Keyboard, under the Keyboard tab. There’s a checkbox there for Use all F1, F2, etc. keys as standard function keys  and if that’s on, the keyboard shortcut will be Function-Command-F1 instead.)

3/ How to delete locked images in Image Capture — Sometimes when you’ve mounted a memory card through a Mac’s SD Card slot or an external card reader, but the card’s tiny lock switch has been flipped on, often by mistake.
Eject the card, then flip the switch to the unlocked position, then mount again. The locks should be gone. If they remain, the card may be damaged. SD cards are tiny computers that manage the wear pattern on what is effectively an SSD. If the on-board chip determines it can’t write data, the only indication would be these locks in Image Capture.
You can copy all the media off and try reformatting in a camera, but if that fails, the card has gone bad.

4/ Record video directly into iMovie in OS X — Start a new project and open the Import window by clicking the Import button in the toolbar. (If you don’t see the Import button, click the Media button in the toolbar, and then click the Import button. If the Image Capture, Photos, or iPhoto window appears, close the window.
In the Cameras section of the Import window sidebar, select the built-in camera. A live video image from the camera appears in the Import window. To specify the event you want to record into, do one of the following:
Choose an existing event — click the Import to pop-up menu at the top of the Import window and choose the event.
Create a new event — Click the Import to pop-up menu, choose New Event, type a name for the new event, and click OK.
Choose the open project — Click the Import to pop-up menu and choose Project Media.
To start recording from the selected camera, click the Record button below the live video image. A new clip is created for each recording. You can repeat this process as many times as necessary. To stop recording, click the Record button again. To end the recording session and return to the iMovie main window, click the Close button.

5/ Deleting locked images from Trash — This one’s a bit complicated. The file permissions associated with trash can get out of whack, making it impossible for OS X to write new files to the Trash folder, but OS X doesn’t have a friendly way to repair it, even though your Mac knows enough that it can’t write to the folder.
The underlying Unix directory for files en route to deletion isn’t global but is located in each user’s home directory. This is transparent to you when using OS X unless the permissions for the directory become messed up. In that case, because OS X can’t move the items you want to delete into this temporary location, you’re prompted to delete files or folders immediately. (You’ll see this warning when deleting files from mounted fileservers, too, for the same reason.)
You can solve this via the Terminal although you need to be even more careful than usual in entering a command there, as you could delete other files if you don’t copy and paste (or, type in) the exact sequence—it won’t just fail, but could delete parts of your drive.
So copy and paste!
With that warning in mind, follow these steps when logged into your account, which has to have administrative privileges for this to work:
Launch Application > Terminal.
At the command prompt type (or, preferably, copy and paste):
sudo rm -ri ~/.Trash
Press the Return key on your keyboard..
You should first be prompted for your account’s password; enter it, and press Return.
You should next be prompted to remove any files and folders in the .Trash folder, followed by the .Trash folder itself. Type yes and return at each prompt. (This is a great place to notice if you’ve entered anything incorrectly above, too, and to press Control-C to halt the removal if you have.)
Now Log out of your OS X account ( > Log Out [user name], which closes all programs) and log back in. The problem should be solved, as OS X will create a new .Trash folder with the correct permissions.
If you continue to have problems, you may have permissions problems on mounted drives. You can repeat the above operation for each volume, which contains a hidden top-level .Trashes folder with separate folders for each user in OS X.
In step 3, instead of ~/.Trash, you use each volume’s name instead. In OS X, you can type df -H to find the names of each volume, which are listed under a Mounted On column in form /Volumes/ plus the drive’s name.
Unix doesn’t recognise spaces in names as part of the name unless they’re handled carefully, by putting a backslash in front of them, such as /Volumes/My\ Main\ Backup\ Drive. You can avoid having to do this formatting by dragging the volume in question into the Terminal window after entering the command for step 2:
Type: sudo rm -ri plus a space (tap the spacebar).
Drag the volume onto the Terminal window, and it inserts the properly formatted volume name.
Now press Delete to remove a space after the drive’s name that’s automatically inserted, and add /.Trashes
Now log out of your account and back in, and you should have your Trash folder restored to normal. (From Macworld.)

Cupertino burglary, significant MacBook Pro overhaul, shipments rise, failure and victories, Flash killing, ArtRage


Police hunting for suspects in burglary at  Cupertino Apple office — Sheriff’s deputies are still scouring San Jose for two suspects thought to have burglarised [Lol, do they mean ‘burgled?!] an Apple office in Cupertino, having already chased down and arrested a third suspect near a Starbucks, according to ongoing reports. Police spotted the trio trying to break into an Apple building at the corner of Bubb Road and Results Way in Cupertino, said ABC7 News. (IE not the company’s main headquarters are located elsewhere, namely 1 Infinite Loop.)

Apple is preparing the ‘first significant overhaul’ of the MacBook Pro in four years — Apple is preparing “the first significant overhaul” of its MacBook Pro laptop line in over four years, reports Bloomberg, quoting unnamed “people familiar with the matter.” However, another rumour says it won’t debut at the iPhone 7 event which  is suspected to take place September 7th.

Meanwhile, MacBook shipments are up — Apple’s MacBook shipments in the second quarter were up 30.3% versus the first quarter, placing the brand on the fifth spot of the half-year ranking, according to global research firm TrendForce. This shipment surge was generated by the release of an upgraded 12-inch model of the latest MacBook.

Apple’s Eddy Cue, Craig Federighi discuss failures and resultant victories — Extending an interview series about the past, present and future of Apple, senior vice presidents Eddy Cue and Craig Federighi talk about the company’s initial failures, a harsh media spotlight, and how it shapes what consumers end up with.

Google Chrome’s plan to kill Flash kicks into high gear — Google’s long-running strategy to kill Flash usage is nearing its endgame this December.

ArtRage painting program for Mac — Indebted to an intuitive interface, ArtRage for Mac OS X for US$49.90 allows you to begin painting without having to learn complex digital tools. Your kit behaves like your real world equivalents. Because of this, you can use techniques that you have already developed in your years of painting. Frank Petrie writes “If you’re a longtime painter, I think that the price is more than fair for an app that provides you with such an unbelievable amount of customization and control.”

Five Tip Friday ~ Become a Mail maestro on Mac and iOS

Image from Mac Observer, where this first tip came from
Image from Mac Observer, where this first tip came from

1/ Mail searches on iDevice — iOS 9 Mail lets you search your emails. Exit Mail by clicking the Home button, then swipe down from the centre of the screen, type in your search term, scroll down to find your Mail results, then tap ‘Search in App’ at top right of the Mail list.

2/ Power-search Mail on iDevice —But did you know iOS responds differently to certain key words? If you type ‘yesterday’ into Mail’s search field, it offers to ‘tokenize’ that and make it a condition of the search, limiting to things dated yesterday.
Once you tokenize a term, you can add another. Here’s the list of words you can tokenise:
Today, Yesterday
Last day, last week, last month, last year
A specific month (‘July 2016’)
A specific year (‘2015’).


3/ Mail Rules in macOS Mail — The Mail app’s Rules let you specify the conditions that trigger actions. A rule can move messages from your inbox to another mailbox; highlight messages from specific senders; automatically reply to or forward messages; and much more.
To create a rule, choose Mail>Preferences, then click Rules. You will see a single rule called News From Apple, included so you wouldn’t have to face a blank window the first time you create a rule.
Double-click this sample Rule or select it and click the Edit button on the right. This sample rule adds a blue background to any message from any of the addresses shown. To add another address, click the + (plus) button
To delete an address, click the – (minus) button on the right of every condition.

4/ Create a new rule to move new messages from a specific sender  to a specific mailbox — Click the Add Rule button, then add a condition to trigger the rule: ‘From’ is equal to [an email address of someone you know].
Next, specify what to do with messages that match either condition: For example, ‘Move message to mailbox Urgent.’
When you click Apply, Active Rules are applied to currently selected mailboxes; if you click Don’t Apply, the Rule is saved and activated for future emails that meet the conditions, but t’s not applied to emails already in selected mailboxes. Either way, from now on, this rule will move messages from either of my editors from my inbox to the Urgent mailbox.

5/ Many conditions, and Rule order — You can specify more than a dozen different conditions in the dropdown menu on the left, and use any of the five options in the dropdown menu in the middle. The dropdown Actions menu (below all of your conditions) includes over a dozen things your rule can do once it meets your specified conditions.
If you have more than two rules, their order matters as Rules are executed sequentially in the order they appear in the Rules window (in Mail >Preferences). So the first rule in the list executes first, then the second rule, then the third, and so on.
To change the order of your rules, just click and drag on a rule and move it up or down in the list.

Extra tip — You can duplicate any rule by selecting it and clicking the Duplicate button on the right of the window. Don’t forget about this feature—it’s often quicker to duplicate and modify a rule than to create a new one from scratch. [These tips for macOS Mail came from Apple World Today.]

Five Tip Friday ~ iTunes has its sidebar back (Mac)

iTunes 12.4 just arrived with the latest Mac OS update (10.11.5) and it adds the sidebar back.

1/ Where is this sidebar? Once you’ve updated iTunes to the latest version, you can click on the View menu at the top of your screen and choose Show Sidebar. Instead of the icons, you now have a drop-down near the top-left of iTunes’ window, from which you’ll select the type of media you want to view. To change what you’re looking at, pick a different option from there.

20160517_Edit2/ Edit the media types — If you only need a few of those media types to show up, pick Edit Menu from that list then turn off the media you don’t ever use.For example, we don’t get TV shows via iTunes here anyway.

3/ Edit the Sidebar — With iTunes 12.4, you can also switch up what’s showing on the new sidebar. To do that, hover over where it says Library and click the Edit button that appears. Select or deselect as your heart desires. (These options change depending on what media type you’re configuring.)
When you’re finished, click Done in the upper-right corner.

4/ Visual changes — If you have been using the Heart button to tell iTunes which tracks you like best so you receive better music recommendations, it only appeared when you hovered your cursor above the track name. Now it’s an ever-apparent heart shape beside the now playing section at the top centre of iTunes. There are two ways to sort a current view: in the iTunes Menu Bar there’s the View>Sort By drop down menu, or you can have them always available on-screen using View>Show View Options (or Hide View Options). Up Next is easier too – the Up Next and AirPlay speakers operators are now much easier to find with their own dedicated buttons on the iTunes toolbar, to the right of the media description.

5/ New features — It’s now much easier to set shuffle or loop commands on tracks and you can see small icons denoting the status visible in the media description/playback in the iTunes menu bar. The Music, Movies, TV Shows, Podcasts, and other media items section at the top left of iTunes has been changed: now you don’t see the most popular items lined up beside each other, but you get a pop-up menu to help you navigate between media types. You can also edit these so you only see the fields you most frequently use.
The Forward and Back buttons at top right in iTunes now help you jump directly between pages you’ve been browsing, just like in a proper browser. This also means you can shift between Apple Music, your music, Movies and so on.

Five Tip Friday ~ Mail: sending large attachments in iOS, Mail Settings Lookup, Auto-Responder

Apple has a page that lets you check your email settings online.
Apple has a page that lets you check your email settings online.

1/ Using Mail Drop in iOS — If you’ve updated to the latest version of iOS 9 on your iPhone or iPad, you have a very handy ability that was only available on the Mac up until now: Mail Drop. This feature will let you send large attachments through email, which is especially great on the iPhone, like a video that is too large to easily share with other people. MailDrop basically uploads the file to an Apple server and sends a download link to that to the recipient – very clever. (This link expires after 30 days; Apple wipes the file from its server.)
This feature is now also built in to iOS 9 now. To use it, all you’ve got  do is, well, use it: select a group of photos or a video that may be too large to send through Mail, and your iOS device will warn you and give you the choice of what to do.

2/ Mail Settings Lookup — Mail Settings Lookup is a free Apple service that can greatly help when setting up an account in the Mail.app (or other email clients). It only works with major email providers like Apple, Gmail, Yahoo!, Hotmail, Mail.com, and a few others. You can’t use it to check the settings of your work email, for instance, not even if your employer uses Gmail on the back end.
Load the page and you get to a form page.
Enter your email address (Apple states it will not store that address). Hit the blue arrow, and you’ll get settings for your incoming email server and outgoing server, too. You can use that information to set up an account in an email client – handy when you want to set up your account on a new Mac or iDevice.

3/ Forwarding multiple emails — If you need to send someone the entire history of correspondence on a project or the trail of an email conversation, open Mail. Either do a search for the messages you need or open the folder they’re in. You’ll have to select them all: if you click on one email and then hold down Shift and click on another, you’ll select everything in between them. Alternatively, hold down the Command key and click on messages, and your Mac will select everything you click on (even if the emails aren’t sitting next to one another).
Now you can click the Forward button in your toolbar (or press Shift-Command-F), and that will start a new email with all of the items you selected in the body of the message.

4/ Forward multiple emails as attachments — Alternatively, forward the selected emails as attachments. Select the emails and then pick Message>Forward as Attachment from the menus at the top or by right-clicking (or hold down the Control key on your keyboard and do a normal click) on one of the emails then choosing that same option from the contextual menu that ‘pops’.

5/ I’m away on holiday — And you can get Mail to do the ‘I’m away’ message for you, you know, like companies do.  In Mail, click on the Mail menu from the menu bar and select Preferences. Select the Rules tab and click on the Add Rule button.
Enter a description for this rule (ie, Auto Reply).
Turn on ‘If ANY of the following conditions are met: Set this section to Account | Exchange’.
Set this section to Reply to Message | Reply message text then click on the Reply message text field to the right to construct your message; ‘I am currently having a wonderful holiday you should all be jealous of and cannot answer my emails until [date’], for example. Or something more considerate … Click OK.
You will now get a message asking if you want to apply this rule to all existing messages. Click Don’t Apply as you only want the rule to work for new messages. Your Out of Office message is now set up.
NOTE: You must remember to disable your Out of Office message manually as it will not turn off automatically. Open the settings again and just uptick this rule so you can use it again another time.

Five Tip Friday ~ Apple Mail in Mac OS


1/ View conversations in Mail — By default, Mail streamlines the message list by grouping messages into conversations, based on the subject lines, dates, senders, recipients, and other information. For example, messages about a birthday party might be grouped into a single conversation.
Only the most recent message of a conversation is shown in the message list. A number in the top message indicates how many of the conversation’s messages are in the current mailbox. Choose View>Organise by Conversation. A checkmark next to the command indicates conversations are on.

2/ Expand or collapse conversations in the message list — For one conversation, click the message count in the top message. For all conversations, choose View>Expand All Conversations or View>Collapse All Conversations.

3/ Step through the messages in a conversation — Press the Option key and while you’re holding it down, the Up Arrow ,or Option-Down Arrow.

4/ Show your original message — If a reply doesn’t show your original message, click the See More link at the bottom of the reply.

5/ Select all messages in a conversation — Choose View>Select>All Messages in this Conversation. You can hide related messages located in other mailboxes: Choose Mail>Preferences, click Viewing, then deselect “Include related messages.”
To hide them only until you quit Mail, choose View>Hide Related Messages. You can also move messages in a conversation: when you move a message to another mailbox, it becomes a related message. If related messages are hidden, the message doesn’t appear in the conversation.
To highlight messages in a conversation: Choose Mail > Preferences, click Viewing, then select “Highlight messages with color when not grouped.”
To change the highlight color, click on the color box.

Extra tips — Delete a conversation: Select a conversation in the messages list, then press Delete. All of the messages in the conversation are deleted, except for related messages located in other mailboxes.
You can see some of your mailboxes in the Favorites bar; all of your mailboxes are shown in the Mail sidebar.

These tips came from Apple Inc.

Five Tip Friday ~ Finding those hidden characters and new Safari speaker button

1/ Quick special characters — If you dabble in graphic design or publishing or you just like writing café properly (instead of cafe) you’ll eventually need hidden typographic characters such as ®, ©, ™, ° and maybe even € and £. The following keyboard shortcuts might be worth memorizing:
© Option-G
® Option-R
™ Option–2
• Option–8
° Shift-Option–8
€ Shift-Option–2
¢ Option–4
… Option-;
“ Option-[
” Shift-Option-[
‘ Option-]
’ Shift-Option-]
These keyboard shortcuts work in any application and in any field into which you can enter text.


2/ Using the Keyboard Viewer — OS X has Keyboard and Character Viewers. The Keyboard Viewer displays an onscreen representation of your Mac’s keyboard, and lets you insert a character into your text just by clicking its key on a virtual keyboard. Choose Show Keyboard Viewer from the Input menu at top-right of your Mac’s menu bar. (If this isn’t visible, open System Preferences in El Capitan, choose Language & Region, click Keyboard Preferences and turn on Show input menu in menu bar. In Yosemite or earlier, it’s in System Preferences>Keyboard, and tick “Show Keyboard & Character Viewers in menu bar’.)
You get a small window with the Command key symbol on it or, if you’ve enabled multiple languages for your keyboard, it looks like a flag instead.
When you first open the Keyboard Viewer, it matches the characters you see on your keyboard, which isn’t very exciting. To view more characters, press and hold modifier keys on your keyboard. For example, if you press and hold the Shift key, the top row of keys changes to a tilde, exclamation point, ampersand, and so on. If you press and hold the Option key, you see even more characters, as shown below.

3/ See special characters as you type — Recent versions of OS X provide an additional way to access the accented or alternate versions of a character while typing. Just as in iOS, hold down the letter’s key for a second and you’ll see a list of alternates appear in a popup menu. To use one of the alternates, either type the number that appears beneath it, or physically click the one you want. To dismiss the menu, either type a different character or press the Escape key. If no additional characters are available for the key you’re holding, the menu won’t appear.

4/ The Character Viewer — The super handy Character Viewer (called ‘Show Emoji & Symbols’ in El Capitan) conveniently clusters the characters in all your active fonts into logical groups. For example, the elusive Ⓟ character lives in the Letterlike Symbols group. Click once to see variations of that character in other fonts, and double-click to insert it into your text. The Character Viewer even remembers the characters you use the most — click ‘Frequently Used’ to see them. You can also add a character to your list of Favorites [sic] by clicking the ‘Add to Favorites’ button beneath its preview on the right.
These Character tips came from Macworld – this post has one more about them.


5/ Quick El Capitan (and Safari 9 for Yosemite) sound tip — You know those annoying sites that immediately start talking or playing music as soon as they load? Now you can turn them off in the Tab bar. Just click the little speaker button. Phew! (This assumes you use Tabbed Browsing, which you can turn on in Safari>Preferences>Tabs … and if you’re not using Tabbed Browsing, you’re not living, believe me.]

Five Tip Friday ~ 5 surprising tips for Photos on Mac

Photos has even finer Levels control than Photoshop
Photos has even finer Levels control than Photoshop

1/ Eight levels — Whereas the Levels adjustment in Photoshop has just three sliders, Photos has eight. This gives you precise control over the brightness levels of all the tones in an image. For example, you can control brightness levels in just the darkest shadows, or just the midtones, or just the lightest highlights, plus in the tones that fall between shadows and midtones, and in the tones that fall between midtones and highlights.
The secret lies in turning the feature on (and this also holds true for Histogram adjustment, below): select an image by double-clicking on it, and then click Edit at top right. Now find the adjust button on the right (it’s the fifth down, between Filters and Retouch) and click that.
Now, click ‘Add’ – it’s in blue near top right. Under Advanced, choose Levels… This gives you awesome control over different spectrums of your images.

All that control!
All that control!

2/ Histogram — You can adjust the RGB histogram, which shows where image data falls in the red, green, and blue graphs superimposed atop each other – or each colour channel’s individual histogram. You can also adjust the luminance channel, which produces a histogram based on how our eyes perceive colour. This hidden talent lies just under that little three-line-and-dot icon the right of the ‘Auto’ button (above).

3/  Add text to any slide in a slideshow project — Activate a slide in a saved slideshow project and click the plus symbol at lower right of the Photos window (not shown). From the resulting menu, choose Add Text. Highlight the placeholder text that appears and enter whatever you want.
You can’t change the position of the text, but you can change fonts, size, and text colour using OS X’s Fonts panel.

4/ Add a custom vignette — You can apply a customisable dark edge vignette to any picture: open an image in Edit mode and then click Adjust (there’s a shortcut for this, BTW — just press the A key on your keyboard).
Now click the Add button at upper right and from the resulting menu, choose Vignette. Use the Radius slider to change the size of the vignette or rather(you may have to activate this by clicking the Disclosure Triangle that appears to the right of the Auto button when you put your cursor there).
Drag the control right to make the vignette bigger or left to make it smaller. Use the Softness slider to control the width of the transition area between what is darkened and what isn’t. Drag it right to increase the feather effect, thereby making the transition wider and softer. Click the blue circle with a white checkmark to toggle the vignette off and on to see a before and after.

5/ Customise Book pages — Have you noticed you can build books in Photos just like you could in iPhoto? It’s under the File menu>Create Book.
Happily, you can change page layouts, swap pictures between pages, and add pictures to pages while you’re viewing all the page thumbnails in a book project. In other words, you don’t have to double-click a page to do it.
This results in a much broader view of the overall book project than you ever had in iPhoto because you can still see all the pages while you’re designing the layout. To swap pictures between pages, click and hold your mouse button until the picture on the page sprouts a blue border, and then drag it atop an image on another page. To move the pages themselves, click to activate them and then drag the handle that appears underneath them.

[These tips came from Macworld, where you’ll find an extra tip.]